1. Field of the Invention
The present invention relates to a multilayered inductor and a method of manufacturing the same.
2. Description of the Related Art
As electronic parts using a ceramic material, there may be provided a capacitor, an inductor, a piezoelectric element, a varistor, a thermistor and the like.
Among these ceramic electronic components, the inductor, together with a resistor and the capacitor, is one of the main passive elements constituting an electronic circuit, and serves to remove noise or to constitute an LC resonance circuit.
Inductors are classified into several types; a wired inductor, manufactured by winding a wire or printing a coil on a ferrite core according to a structure thereof and forming electrodes at both ends thereof, a multilayered inductor, manufactured by printing internal electrodes on a magnetic material or a dielectric material and then laminating layers thereof in plural, or a thin film inductor, and the like.
The multilayered inductor may be miniaturized, have a relatively reduced thickness and have strengths in terms of DC resistance, as compared to the wired inductor, such that it is widely used in a power supply circuit or the like required to be miniaturized and have high capacitance.
The multilayered inductor may be manufactured in a laminate form in which a plurality of ceramic sheets formed of a number of ferrites or the dielectric material having low-k dielectric, are laminated in vertical direction.
A coil-shaped metal pattern is formed on each ceramic sheet. The coil-shaped metal patterns formed on respective ceramic sheets are sequentially connected to each other through conductive vias formed in the respective ceramic sheets, and overlapped with each other in a laminated direction, thereby constituting a coil part having a spiral structure.
The multilayered inductor may be manufactured as a separate component in a chip shape, or may be formed together with other modules embedded in a substrate, if necessary.
Meanwhile, among the inductors, there is provided a so called “power inductor” having high current.
The power inductor is mainly used in a power supply circuit such as a DC-DC converter in a portable device, which requires small inductance (L) value change rate for used current and temperature.
The multilayered power inductor may be reduced in thickness to have strengths in miniaturization and DC resistance as compared to the wired power inductor, however, the multilayered power inductor may be greatly affected structurally by an open magnetic path, whereby a change in inductance (L) value according to the current application is large.
In order to solve this defect, the multilayered power inductor according to the related art partially includes a nonmagnetic Gap layer in an inner structure thereof to reduce magnetic flux, thereby improving a change characteristic in inductance (L) value according to a current application.